Oleuropein induces apoptosis via abrogating NF‐κB activation cascade in estrogen receptor–negative breast cancer cells

Discovery of oxazine-linked pyrimidine as an inhibitor of breast cancer growth and metastasis by abrogating NF-κB activation

Introduction

Nuclear factor kappa (NF-κB) plays a key role in cancer cell proliferation; thus, small molecule inhibitors of NF-κB activity can effectively inhibit breast cancer (BC) progression. We have previously reported oxazine and piperazine-linked pyrimidines as novel anti-cancer agents that can suppress NF-κB activation in BC cells. Moreover, the TRX-01 compound, an oxazine-linked pyrimidine, inhibited MCF-7 cells at a concentration of 9.17 µM in the Alamar Blue assay.

Methods

This work involved the analysis of frontier molecular orbitals, HOMO-LUMO interactions, and molecular electrostatic potential for the TRX-01 structure. Additionally, the TRX-01 compound was studied for cytotoxicity, and migration as well as invasion assays were performed on BC cells.

Results

Finally, TRX-01 blocked the translocation of NF-κB from the cytoplasm to the nucleus in MCF-7 cells and reduced NF-κB and IκBα levels in a dose-dependent manner. It also suppressed migratory and invasive properties of BC cells.

Conclusion

Overall, the data indicates that TRX-01 can function as a novel blocker of BC growth and metastasis by targeting NF-κB activation.

Kalanchoe pinnata (Lam.) Pers. Leaf ethanolic extract exerts selective anticancer activity through ROS-induced apoptotic cell death in human cancer cell lines

BACKGROUND

The leaves of Kalanchoe pinnata (Lam.) Pers. (K. pinnata), a succulent plant native to tropical regions, are used as a medicinal alternative against cancer in several countries worldwide; however, its therapeutic potential to fight cancer has been little addressed. In this study, we analyzed the phytochemical content, antioxidant capacity, and selectivity of K. pinnata leaf ethanolic extract against different human cancer cell lines in vitro.

METHODOLOGY

This study subjected the ethanolic extract to enzymatic assays to quantify the phytochemical content (phenolics, flavonoids, and anthraquinones) and its radical scavenging and iron-reducing capacities. Also, the phytoconstituents and major phenolic compounds present in the extract's subfractions were identified by GC-MS, HPLC, and NMR. Human cancer (MCF-7, PC-3, HT-29) and normal colon (CoN) cell lines were treated with different concentrations of K. pinnata leaf ethanolic extract, and the changes in cell proliferation (sulforhodamine B assay), caspases activity (FITC-VAD-FMK reporter), mitochondrial membrane potential (MMP, rhodamine 123 assay), chromatin condensation/fragmentation (Hoechst 33342 stain), and ROS generation (DCFH2 probe assay) were assessed.

RESULTS

The results showed that the K. pinnata leaf ethanolic extract is rich in phytoconstituents with therapeutic potential, including phenols (quercetin and kaempferol), flavonoids, fatty acid esters (34.6% of the total composition), 1- triacontanol and sterols (ergosterol and stigmasterol, 15.4% of the total composition); however, it presents a poor content of antioxidant molecules (IC50 = 27.6 mg/mL for H2O2 scavenging activity vs. 2.86 mg/mL in the case of Trolox). Notably, the extract inhibited cell proliferation and reduced MMP in all human cell lines tested but showed selectivity for HT-29 colon cancer cells compared to CoN normal cells (SI = 8.4). Furthermore, ROS generation, caspase activity, and chromatin condensation/fragmentation were augmented significantly in cancer-derived cell lines, indicating a selective cytotoxic effect.

CONCLUSION

These findings reveal that the K. pinnata leaf ethanolic extract contains several bioactive molecules with therapeutic potential, capable of displaying selective cytotoxicity in different human cancer cell lines.

Oleuropein impact on colorectal cancer

Colorectal cancer (CRC) is considered the third most common cancer in the world. In Mediterranean region, olives and olive oil play a substantial role in diet and medical traditional behaviors. They totally believe that high consumption of olive products can treat a wide range of diseases and decrease risk of illness. Oleuropein is the main active antioxidant molecule found in pre-mature olive fruit and leaves. Recently, it has been demonstrated that oleuropein is used in cancer therapy as an anti-proliferative and apoptotic agent for some cancer cells. In this review, we would like to explore the conclusive effects of oleuropein on CRC with respect to in vitro and in vivo studies.

Oleuropein activates autophagy to circumvent anti-plasmodial defense

Antimalarial drug resistance and unavailability of effective vaccine warrant for newer drugs and drug targets. Hence, anti-inflammatory activity of phyto-compound (oleuropein; OLP) was determined in antigen (LPS)-stimulated human THP-1 macrophages (macrophage model of inflammation; MMI). Reduction in the inflammation was controlled by the PI3K-Akt1 signaling to establish the "immune-homeostasis." Also, OLP treatment influenced the cell death/autophagy axis leading to the modulated inflammation for extended cell survival. The findings with MII prompted us to detect the antimalarial activity of OLP in the wild type (3D7), D10-expressing GFP-Atg18 parasite, and chloroquine-resistant (Dd2) parasite. OLP did not show the parasite inhibition in the routine in vitro culture of P. falciparum whereas OLP increased the antimalarial activity of artesunate. The molecular docking of autophagy-related proteins, investigations with MMI, and parasite inhibition assays indicated that the host activated the autophagy to survive OLP pressure. The challenge model of P. berghei infection showed to induce autophagy for circumventing anti-plasmodial defenses.

Oleuropein induces apoptosis in gastric cancer cell lines by regulating mir-34a, mir-21, and related genes: An experimental and bioinformatic study

Gastric Cancer (GC) is one of the most prevalent malignancies worldwide. Oleuropein, as a natural phenolic compound with anti-cancer characteristics, is a good option with low side effects to overcome the adverse impact of conventional treatments in cancer. This research evaluated Oleuropein's anti-cancer and apoptotic activities and the anti-migratory effects by modulating potential target genes in epithelial-mesenchymal transition (EMT). Bioinformatic analysis was performed to predict possible Oleuropein's target genes. Then the importance of these genes was shown by UALCAN, Gene Expression Omnibus (GEO), and The Cancer Genome Atlas (TCGA) datasets in gastric cancer. Finally, the association between the selected genes was shown by Cytoscape network analysis. The MTT assay, DAPI staining, flow cytometry, and real-time PCR were applied in the current study. The results showed that the viability of cells was decreased, and the apoptosis rate increased in the Oleuropein-treated group. These findings revealed that Oleuropein regulated the expression of the apoptotic and metastatic genes and microRNAs in GC cells.

Olea europaea L-derived secoiridoids: Beneficial health effects and potential therapeutic approaches

Over the years, health challenges have become increasingly complex and global and, at the beginning of the 21st century, chronic diseases, including cardiovascular, neurological, and chronic respiratory diseases, as well as cancer and diabetes, have been identified by World Health Organization as one of the biggest threats to human health. Recently, antimicrobial resistance has also emerged as a growing problem of public health for the management of infectious diseases. In this scenario, the exploration of natural products as supplementation or alternative therapeutic options is acquiring great importance, and, among them, the olive tree, Olea europaea L, specifically leaves, fruits, and oil, has been increasingly investigated for its health promoting properties. Traditionally, these properties have been largely attributed to the high concentration of monounsaturated fatty acids, although, in recent years, beneficial effects have also been associated to other components, particularly polyphenols. Among them, the most interesting group is represented by Olea europaea L secoiridoids, comprising oleuropein, oleocanthal, oleacein, and ligstroside, which display anti-inflammatory, antioxidant, cardioprotective, neuroprotective and anticancer activities. This review provides an overview of the multiple health beneficial effects, the molecular mechanisms, and the potential applications of secoiridoids from Olea europaea L.

Biosynthesis and Anticancer Activity of Genistein Glycoside Derivatives

As a beneficial natural flavonoid, genistein has demonstrated a wide range of biological functions via regulating a number of targets and signaling pathways, such as anti-cancer, antioxidant, antibacterial, antiinflammatory, antifungal, antiviral, iron chelation, anti-obesity, anti-diabetes, and anti-hypertension. Pub- Med/Medline and Web of Science were searched using appropriate keywords until the end of December 2023. Despite its many potential benefits, genistein's clinical application is limited by low hydrophilicity, poor solubility, and suboptimal bioavailability due to its structure. These challenges can be addressed through the conversion of genistein into glycosides. Glycosylation of active small molecules may enhance their solubility, stability, and biological activity. In recent years, extensive research has been conducted on the synthesis, properties, and anticancer activity of glycoconjugates. Previous reviews were devoted to discussing the biological activities of genistin, with a little summary of the biosynthesis and the structure-activity relationship for their anticancer activity of genistein glycoside derivatives. Therefore, we summarized recent advances in the biosynthesis of genistein glycosylation and discussed the antitumor activities of genistein glycoside derivatives in a structure-activity relationship, which may provide important information for further development of genistein derivatives.

Oleuropein exhibits anticarcinogen effects against gastric cancer cell lines

BACKGROUND

Oleuropein (OLE), the main phenolic compound of the olive fruit and leaves, has many heathful effects. Gastric cancer is the most fatal malignancy in many parts of the world and it is generally related to harmful dietetic factors. The anticarcinogenic role of OLE in gastric cancer has not been studied sufficiently yet. In this study, we aimed to research the cytotoxic, genotoxic and apoptotic effects of OLE on gastric adenocancer (AGS) cells in vitro.

METHODS AND RESULTS

A standard cell line derived from gastric adeno cancer (AGS) cells was employed, and its performance following a 24-hour exposure to OLE at various doses was examined. The ATP cell viability assay, 2',7'-dichlorodihydrofluorescein-diacetate assay (H2DCF-DA) and alkaline single cell gel electrophoresis assay (Comet Assay) were used to study the cytotoxicity, production of reactive oxygen species (ROS) and genotoxicity respectively. The induction of apoptosis was discovered using flow cytometry. OLE reduced AGS cells viability about 60% at maximum concentration (500 µmol/L) and also resulted in approximately 100% DNA damage and about 40% apoptosis with necrosis in AGS cells depending on the increased doses. Cell viability was also significantly decreased in relation to increased intracellular reactive oxygen species (ROS) levels (p < 0.05 - 0.001).

CONCLUSIONS

Oleuropein has shown significant anticarcinogen effects against gastric adenocancer (AGS) cells in vitro. Oleuropein, a nutrient rich in olive and olive oil, seems to be both protective and therapeutic against gastric cancer and may be a new chemotherapeutic agent in the future.

Antiproliferative and Apoptotic Effects of Olive Leaf Extract Microcapsules on MCF-7 and A549 Cancer Cells

Alginate microcapsules are a talented means for the delivery of broad curative biomacromolecules. In this study, we immobilized olive leaf extract (OLE) by calcium alginate (CA) and chitosan-coated CA (CCA) and characterized the OLE-loaded CA and CCA. The cytotoxic effect, the cell cycle arrest, and the apoptotic effect of OLE and its microcapsules were investigated against breast adenocarcinoma (MCF-7) and lung carcinoma (A549). As a result, the loading capacity of OLE-CA and OLE-CCA was found to be 80 and 99%, respectively, in optimal conditions. Also, OLE-CA and OLE-CCA were characterized by unique FTIR peaks and morphological display relative to the empty CCA microcapsules. The cytotoxicity analysis showed that the IC50 values of OLE-CA and OLE-CCA were determined to be 312 and 0.94 μg mL-1 against A549, respectively, whereas these were found to be 865.4 and 425.5 μg mL-1 for MCF-7 cells. On the other hand, the OLE microcapsules did not possess in any concentration of cytotoxic influence on the BEAS 2B healthy cell line. Also, the exposure of OLE-CCA to MCF-7 and A549 resulted in the arrest of more MCF-7 and A549 cells at the G0/G1 phase compared to the OLE. A549 and MCF-7 cells were predominantly found in the late apoptosis phase and necrosis phase, respectively. Optical microscopy images confirmed that OLE microcapsules were more effective against MCF-7 and A549 than free OLE. The present work suggested that the OLE microcapsules might be administered as nutrition supplements for cancer therapy.

Graphene oxide nanoarchitectures in cancer biology: Nano-modulators of autophagy and apoptosis

Nanotechnology is a growing field, with many potential biomedical applications of nanomedicine for the treatment of different diseases, particularly cancer, on the horizon. Graphene oxide (GO) nanoparticles can act as carbon-based nanocarriers with advantages such as a large surface area, good mechanical strength, and the capacity for surface modification. These nanostructures have been extensively used in cancer therapy for drug and gene delivery, photothermal therapy, overcoming chemotherapy resistance, and for imaging procedures. In the current review, we focus on the biological functions of GO nanoparticles as regulators of apoptosis and autophagy, the two major forms of programmed cell death. GO nanoparticles can either induce or inhibit autophagy in cancer cells, depending on the conditions. By stimulating autophagy, GO nanocarriers can promote the sensitivity of cancer cells to chemotherapy. However, by impairing autophagy flux, GO nanoparticles can reduce cell survival and enhance inflammation. Similarly, GO nanomaterials can increase ROS production and induce DNA damage, thereby sensitizing cancer cells to apoptosis. In vitro and in vivo experiments have investigated whether GO nanomaterials show any toxicity in major body organs, such as the brain, liver, spleen, and heart. Molecular pathways, such as ATG, MAPK, JNK, and Akt, can be regulated by GO nanomaterials, leading to effects on autophagy and apoptosis. These topics are discussed in this review to shed some lights towards the biomedical potential of GO nanoparticles and their biocompatibility, paving the way for their future application in clinical trials.

Iridoid Derivatives as Anticancer Agents: An Updated Review from 1970-2022

The rise of cancer cases has coincided with the urgent need for the development of potent chemical entities and/or modification of existing commodities to improve their efficacy. Increasing evidence suggests that cancer remains one of the leading causes of death globally, with colon cancer cases alone likely to rise exponentially by 2030. The exponential rise in cancer prevalence is largely attributable to the growing change toward a sedentary lifestyle and modern diets, which include genetically modified foods. At present, the prominent treatments for cancer are chemotherapy, surgery, and radiation. Despite slowing cancer progression, these treatments are known to have devastating side effects that may deteriorate the health of the patient, thus, have a low risk-benefit ratio. In addition, many cancer drugs have low bioavailability, thereby limiting their therapeutic effects in cancer patients. Moreover, the drastic rise in the resistance of neoplastic cells to chemotherapeutic agents is rendering the use of some drugs ineffective, thereby signaling the need for more anticancer chemical entities. As a result, the use of natural derivatives as anticancer agents is gaining considerable attention. Iridoids have the potential to form conjugates with other anticancer, antidiabetic, antileishmanial, and antimalarial drugs, which synergistically have the potential to increase their effects. Published studies have identified the role of iridoids, which, if fully explored, may result in cheaper and less toxic alternative/adjuvant cancer drugs. The subject of this article is natural and synthetic iridoid derivatives and their potential therapeutic roles as anticancer agents.

Olive leaves extract alleviates inflammation and modifies the intrinsic apoptotic signal in the leukemic bone marrow

Introduction

Current anti-leukemic chemotherapies with multiple targets suffer from side effects. Synthetic drugs with huge off-target effects are detrimental to leukemic patients. Therefore, natural plant-based products are being increasingly tested for new anti-leukemic therapy with fewer or no side effects. Herein, we report the effect of ethanolic olive leaves extract (EOLE) on the K562 cell line and on the bone marrow (BM) of N-ethyl-N-nitrosourea (ENU)-induced leukemic mice.

Methods

Using standard methodologies, we assessed viability, chromatin condensation, and induction of apoptosis in EOLE-treated K562 cells in-vitro. The anti-leukemic activity of EOLE was assayed by measuring ROS, levels of various cytokines, expression of iNOS and COX-2 gene, and changes in the level of important apoptosis regulatory and cell signaling proteins in-vivo.

Result

K562 cells underwent apoptotic induction after exposure to EOLE. In the BM of leukemic mice, EOLE therapy decreased the number of blast cells, ROS generation, and expression of NF-κB and ERK1/2. IL-6, IL-1β, TNF-α, iNOS, and COX-2 were among the inflammatory molecules that were down-regulated by EOLE therapy. Additionally, it decreased the expression of anti-apoptotic proteins BCL2A1, BCL-xL, and MCL-1 in the BM of leukemic mice.

Discussion

Chronic inflammation and anomalous apoptotic mechanism both critically contribute to the malignant transformation of cells. Inflammation in the tumor microenvironment promotes the growth, survival, and migration of cancer cells, accelerating the disease. The current investigation showed that EOLE treatment reduces inflammation and alters the expression of apoptosis regulatory protein in the BM of leukemic mice, which may halt the progression of the disease.

Nano-Zirconium Dioxide Catalyzed Multicomponent Synthesis of Bioactive Pyranopyrazoles That Target Cyclin Dependent Kinase 1 in Human Breast Cancer Cells

Small molecules are being used to inhibit cyclin dependent kinase (CDK) enzymes in cancer treatment. There is evidence that CDK is a drug-target for cancer therapy across many tumor types because it catalyzes the transfer of the terminal phosphate of ATP to a protein that acts as a substrate. Herein, the identification of pyranopyrazoles that were CDK inhibitors was attempted, whose synthesis was catalyzed by nano-zirconium dioxide via multicomponent reaction. Additionally, we performed an in-situ analysis of the intermediates of multicomponent reactions, for the first-time, which revealed that nano-zirconium dioxide stimulated the reaction, as estimated by Gibbs free energy calculations of spontaneity. Functionally, the novel pyranopyrazoles were tested for a loss of cell viability using human breast cancer cells (MCF-7). It was observed that compounds 5b and 5f effectively produced loss of viability of MCF-7 cells with IC₅₀ values of 17.83 and 23.79 µM, respectively. In vitro and in silico mode-of-action studies showed that pyranopyrazoles target CDK1 in human breast cancer cells, with lead compounds 5b and 5f having potent IC₅₀ values of 960 nM and 7.16 μM, respectively. Hence, the newly synthesized bioactive pyranopyrazoles could serve as better structures to develop CDK1 inhibitors against human breast cancer cells.

The Double-Edged Sword of Oleuropein in Ovarian Cancer Cells: From Antioxidant Functions to Cytotoxic Effects

Oleuropein plays a key role as a pro-oxidant as well as an antioxidant in cancer. In this study, the activity of oleuropein, in an in vitro model of ovarian (OCCs) and breast cancer cells (BCCs) was investigated. Cell viability and cell death were analyzed. Oxidative stress was measured by CM-H2DCFDA flow cytometry assay. Mitochondrial dysfunction was evaluated based on mitochondrial reactive oxygen species (ROS) and GPX4 protein levels. Further, the effects on iron metabolism were analyzed by measuring the intracellular labile iron pool (LIP). We confirmed that high doses of oleuropein show anti-proliferative and pro-apoptotic activity on HEY and MCF-7 cells. Moreover, our results indicate that low doses of oleuropein impair cell viability without affecting the mortality of cells, and also decrease the LIP and ROS levels, keeping them unchanged in MCF-7 cells. For the first time, our data show that low doses of oleuropein reduce erastin-mediated cell death. Interestingly, oleuropein decreases the levels of intracellular ROS and LIP in OCCs treated with erastin. Noteworthily, we observed an increased amount of ROS scavenging enzyme GPX4 together with a consistent reduction in mitochondrial ROS, confirming a reduction in oxidative stress in this model.

Nimbolide enhances the antitumor effect of docetaxel via abrogation of the NF-κB signaling pathway in prostate cancer preclinical models

Prostate cancer is the second most frequent type of cancer that affects men. Docetaxel (DTX) administration is the front-line therapy for patients with advanced prostate cancer and unfortunately, half of these patients develop resistance to DTX which could be due to its ability to activate the NF-κB pathway. The combinational effect of DTX and nimbolide on proliferation, apoptosis, activation of NF-κB, DNA binding ability of NF-κB, and expression of NF-κB-targeted gene products was investigated. The antitumor and antimetastatic effect of DTX or NL alone or in combination was also examined. The co-administration of NL and DTX resulted in a significant loss of cell viability with enhanced apoptosis in DTX-sensitive/resistant prostate cancer cells. NL abrogated DTX-triggered NF-κB activation and expression of its downstream antiapoptotic factors (survivin, Bcl-2, and XIAP). The combination of NL and DTX significantly reduced the DNA binding ability of NF-κB in both cell types. NL significantly enhanced the antitumor effect of DTX and reduced metastases in orthotopic models of prostate cancer. NL abolishes DTX-induced-NF-κB activation to counteract cell proliferation, tumor growth, and metastasis in the prostate cancer models.

Unraveling the Potential Role of NEDD4-like E3 Ligases in Cancer

Cancer is a deadly disease worldwide, with an anticipated 19.3 million new cases and 10.0 million deaths occurring in 2020 according to GLOBOCAN 2020. It is well established that carcinogenesis and cancer development are strongly linked to genetic changes and post-translational modifications (PTMs). An important PTM process, ubiquitination, regulates every aspect of cellular activity, and the crucial enzymes in the ubiquitination process are E3 ubiquitin ligases (E3s) that affect substrate specificity and must therefore be carefully regulated. A surfeit of studies suggests that, among the E3 ubiquitin ligases, neuronal precursor cell-expressed developmentally downregulated 4 (NEDD4)/NEDD4-like E3 ligases show key functions in cellular processes by controlling subsequent protein degradation and substrate ubiquitination. In addition, it was demonstrated that NEDD4 mainly acts as an oncogene in various cancers, but also plays a tumor-suppressive role in some cancers. In this review, to comprehend the proper function of NEDD4 in cancer development, we summarize its function, both its tumor-suppressive and oncogenic role, in multiple types of malignancies. Moreover, we briefly explain the role of NEDD4 in carcinogenesis and progression, including cell survival, cell proliferation, autophagy, cell migration, invasion, metastasis, epithelial-mesenchymal transition (EMT), chemoresistance, and multiple signaling pathways. In addition, we briefly explain the significance of NEDD4 as a possible target for cancer treatment. Therefore, we conclude that targeting NEDD4 as a therapeutic method for treating human tumors could be a practical possibility.

Resveratrol in breast cancer treatment: from cellular effects to molecular mechanisms of action

Breast cancer (BC) is one of the most common cancers in females and is responsible for the highest cancer-related deaths following lung cancer. The complex tumor microenvironment and the aggressive behavior, heterogenous nature, high proliferation rate, and ability to resist treatment are the most well-known features of BC. Accordingly, it is critical to find an effective therapeutic agent to overcome these deleterious features of BC. Resveratrol (RES) is a polyphenol and can be found in common foods, such as pistachios, peanuts, bilberries, blueberries, and grapes. It has been used as a therapeutic agent for various diseases, such as diabetes, cardiovascular diseases, inflammation, and cancer. The anticancer mechanisms of RES in regard to breast cancer include the inhibition of cell proliferation, and reduction of cell viability, invasion, and metastasis. In addition, the synergistic effects of RES in combination with other chemotherapeutic agents, such as docetaxel, paclitaxel, cisplatin, and/or doxorubicin may contribute to enhancing the anticancer properties of RES on BC cells. Although, it demonstrates promising therapeutic features, the low water solubility of RES limits its use, suggesting the use of delivery systems to improve its bioavailability. Several types of nano drug delivery systems have therefore been introduced as good candidates for RES delivery. Due to RES's promising potential as a chemopreventive and chemotherapeutic agent for BC, this review aims to explore the anticancer mechanisms of RES using the most up to date research and addresses the effects of using nanomaterials as delivery systems to improve the anticancer properties of RES.

Demystifying the Functional Role of Nuclear Receptors in Esophageal Cancer

Esophageal cancer (EC), an aggressive and poorly understood disease, is one of the top causes of cancer-related fatalities. GLOBOCAN 2020 reports that there are 544,076 deaths and 604,100 new cases expected worldwide. Even though there are various advancements in treatment procedures, this cancer has been reported as one of the most difficult cancers to cure, and to increase patient survival; treatment targets still need to be established. Nuclear receptors (NRs) are a type of transcription factor, which has a key role in several biological processes such as reproduction, development, cellular differentiation, stress response, immunity, metabolism, lipids, and drugs, and are essential regulators of several diseases, including cancer. Numerous studies have demonstrated the importance of NRs in tumor immunology and proved the well-known roles of multiple NRs in modulating proliferation, differentiation, and apoptosis. There are surplus of studies conducted on NRs and their implications in EC, but only a few studies have demonstrated the diagnostic and prognostic potential of NRs. Therefore, there is still a paucity of the role of NRs and different ways to target them in EC cells to stop them from spreading malignancy. This review emphasizes the significance of NRs in EC by discussing their diverse agonists as well as antagonists and their response to tumor progression. Additionally, we emphasize NRs’ potential to serve as a novel therapeutic target and their capacity to treat and prevent EC.

Potential Application of Leelamine as a Novel Regulator of Chemokine-Induced Epithelial-to-Mesenchymal Transition in Breast Cancer Cells

CXCR7 and CXCR4 are G protein-coupled receptors (GPCRs) that can be stimulated by CXCL12 in various human cancers. CXCR7/4–CXCL12 binding can initiate activation of multiple pathways including JAK/STAT and manganese superoxide dismutase (MnSOD) signaling, and initiate epithelial–mesenchymal transition (EMT) process. It is established that cancer cell invasion and migration are caused because of these events. In particular, the EMT process is an important process that can determine the prognosis for cancer. Since the antitumor effect of leelamine (LEE) has been reported in various previous studies, here, we have evaluated the influence of LEE on the CXCR7/4 signaling axis and EMT processes. We first found that LEE suppressed expression of CXCR7 and CXCR4 both at the protein and mRNA levels, and showed inhibitory effects on these chemokines even after stimulation by CXCL12 ligand. In addition, LEE also reduced the level of MnSOD and inhibited the EMT process to attenuate the invasion and migration of breast cancer cells. In addition, phosphorylation of the JAK/STAT pathway, which acts down-stream of these chemokines, was also abrogated by LEE. It was also confirmed that LEE can induce an imbalance of GSH/GSSG and increases ROS, thereby resulting in antitumor activity. Thus, we establish that targeting CXCR7/4 in breast cancer cells can not only inhibit the invasion and migration of cancer cells but also can affect JAK/STAT, EMT process, and production of ROS. Overall, the findings suggest that LEE can function as a novel agent affecting the breast cancer.

Traditional Medicinal Plants as a Source of Inspiration for Osteosarcoma Therapy

Osteosarcoma is one of the most common types of bone cancers among paediatric patients. Despite the advances made in surgery, chemo-, and radiotherapy, the mortality rate of metastatic osteosarcoma remains unchangeably high. The standard drug combination used to treat this bone cancer has remained the same for the last 20 years, and it produces many dangerous side effects. Through history, from ancient to modern times, nature has been a remarkable source of chemical diversity, used to alleviate human disease. The application of modern scientific technology to the study of natural products has identified many specific molecules with anti-cancer properties. This review describes the latest discovered anti-cancer compounds extracted from traditional medicinal plants, with a focus on osteosarcoma research, and on their cellular and molecular mechanisms of action. The presented compounds have proven to kill osteosarcoma cells by interfering with different pathways: apoptosis induction, stimulation of autophagy, generation of reactive oxygen species, etc. This wide variety of cellular targets confer natural products the potential to be used as chemotherapeutic drugs, and also the ability to act as sensitizers in drug combination treatments. The major hindrance for these molecules is low bioavailability. A problem that may be solved by chemical modification or nano-encapsulation.

A Comprehensive Review on the Anti-Cancer Effects of Oleuropein

In Mediterranean cuisine and culture, olive oil and olive fruits play a significant role. Many people believe that those who consume olive oil and its fruit live longer and have a decreased risk of illness. Olive leaves were used to treat a range of diseases in ancient times, including malaria fever and lower earaches. Although it was not understood at the time what key components were responsible for these effects because they had not yet been discovered, Oleuropein is now recognized as one of the primary elements in immature olive fruits and leaves. Later research was carried out to determine the effects of this molecule, and it was determined that it functions as an antioxidant. Oleuropein consumption has aided in cancer treatment over the years, and this was assumed to be owing to its antioxidant properties. Oleuropein’s effects on cancer, however, go beyond that; it is now known that Oleuropein functions as both an anti-proliferative and an apoptotic promoter in many cancer cells. The kinetics and dosages of Oleuropein and the mechanisms behind its involvement and effects in cancer are explored in this review. Finally, the effects of Oleuropein in combination with anticancer medicines are investigated.

Molecular Landscape of LncRNAs in Prostate Cancer: A focus on pathways and therapeutic targets for intervention

Background

One of the most malignant tumors in men is prostate cancer that is still incurable due to its heterogenous and progressive natures. Genetic and epigenetic changes play significant roles in its development. The RNA molecules with more than 200 nucleotides in length are known as lncRNAs and these epigenetic factors do not encode protein. They regulate gene expression at transcriptional, post-transcriptional and epigenetic levels. LncRNAs play vital biological functions in cells and in pathological events, hence their expression undergoes dysregulation.

Aim of review

The role of epigenetic alterations in prostate cancer development are emphasized here. Therefore, lncRNAs were chosen for this purpose and their expression level and interaction with other signaling networks in prostate cancer progression were examined.

Key scientific concepts of review

The aberrant expression of lncRNAs in prostate cancer has been well-documented and progression rate of tumor cells are regulated via affecting STAT3, NF-κB, Wnt, PI3K/Akt and PTEN, among other molecular pathways. Furthermore, lncRNAs regulate radio-resistance and chemo-resistance features of prostate tumor cells. Overexpression of tumor-promoting lncRNAs such as HOXD-AS1 and CCAT1 can result in drug resistance. Besides, lncRNAs can induce immune evasion of prostate cancer via upregulating PD-1. Pharmacological compounds such as quercetin and curcumin have been applied for targeting lncRNAs. Furthermore, siRNA tool can reduce expression of lncRNAs thereby suppressing prostate cancer progression. Prognosis and diagnosis of prostate tumor at clinical course can be evaluated by lncRNAs. The expression level of exosomal lncRNAs such as lncRNA-p21 can be investigated in serum of prostate cancer patients as a reliable biomarker.

Oleuropein Counteracts Both the Proliferation and Migration of Intra- and Extragonadal Seminoma Cells

Recent and growing literature has reported that oleuropein (OLE), the main polyphenol in olive leaf extract, inhibits tumor cell proliferation and reduces the invasiveness properties of cancer cells; therefore, OLE may play a significant role in the development of new drugs for cancer treatment. These antineoplastic properties have been reported in many experimental cancer models, but the effect of OLE on seminoma cells is yet to be evaluated. In the present study, we demonstrate, for the first time, that OLE reduces cell viability in both intra- and extragonadal TCAM-2 and SEM-1 seminoma cells, respectively, in a dose-dependent manner. As shown by Western-blot analysis, OLE exposure reduced cyclin-D1 expression and upregulated p21^Cip/WAF1, concomitantly affecting the upstream pathway of NF-κB, leading to the reduction of its nuclear content, thereby suggesting that OLE could modulate cell-cycle regulators by inhibiting NF-κB. Moreover, Annexin V staining revealed that OLE induced apoptosis in cancer cells and upregulated the pro-apoptotic factor BAX. Through wound-healing scratch and transmigration assays, we also demonstrated that OLE significantly reduced the migration and motility of TCAM-2 and SEM-1 cells, and downregulated the expression of TGFβ-1, which is known to be the main pro-fibrotic factor involved in the acquisition of the migratory and invasive properties of cancer cells. Collectively, our results indicate that OLE reduces seminoma cell proliferation, promotes apoptosis, and counteracts cell migration and motility. Further studies are needed to explore the molecular mechanisms underlying these observed effects.

Targeting Nuclear Receptors in Lung Cancer—Novel Therapeutic Prospects

Lung cancer, the second most commonly diagnosed cancer, is the major cause of fatalities worldwide for both men and women, with an estimated 2.2 million new incidences and 1.8 million deaths, according to GLOBOCAN 2020. Although various risk factors for lung cancer pathogenesis have been reported, controlling smoking alone has a significant value as a preventive measure. In spite of decades of extensive research, mechanistic cues and targets need to be profoundly explored to develop potential diagnostics, treatments, and reliable therapies for this disease. Nuclear receptors (NRs) function as transcription factors that control diverse biological processes such as cell growth, differentiation, development, and metabolism. The aberrant expression of NRs has been involved in a variety of disorders, including cancer. Deregulation of distinct NRs in lung cancer has been associated with numerous events, including mutations, epigenetic modifications, and different signaling cascades. Substantial efforts have been made to develop several small molecules as agonists or antagonists directed to target specific NRs for inhibiting tumor cell growth, migration, and invasion and inducing apoptosis in lung cancer, which makes NRs promising candidates for reliable lung cancer therapeutics. The current work focuses on the importance of various NRs in the development and progression of lung cancer and highlights the different small molecules (e.g., agonist or antagonist) that influence NR expression, with the goal of establishing them as viable therapeutics to combat lung cancer.

NF-κB as a regulator of cancer metastasis and therapy response: A focus on epithelial-mesenchymal transition

Metastasis of tumor cells is a complex challenge and significantly diminishes the overall survival and prognosis of cancer patients. The epithelial-to-mesenchymal transition (EMT) is a well-known mechanism responsible for the invasiveness of tumor cells. A number of molecular pathways can regulate the EMT mechanism in cancer cells and nuclear factor-kappaB (NF-κB) is one of them. The nuclear translocation of NF-κB p65 can induce the transcription of several genes involved in EMT induction. The present review describes NF-κB and EMT interaction in cancer cells and their association in cancer progression. Due to the oncogenic role NF-κB signaling, its activation enhances metastasis of tumor cells via EMT induction. This has been confirmed in various cancers including brain, breast, lung and gastric cancers, among others. The ZEB1/2, transforming growth factor-β, and Slug as inducers of EMT undergo upregulation by NF-κB to promote metastasis of tumor cells. After EMT induction driven by NF-κB, a significant decrease occurs in E-cadherin levels, while N-cadherin and vimentin levels undergo an increase. The noncoding RNAs can potentially also function as upstream mediators and modulate NF-κB/EMT axis in cancers. Moreover, NF-κB/EMT axis is involved in mediating drug resistance in tumor cells. Thus, suppressing NF-κB/EMT axis can also promote the sensitivity of cancer cells to chemotherapeutic agents.

Influence of Olive Oil and Its Components on Breast Cancer: Molecular Mechanisms

Breast cancer is the most frequent malignant neoplasia and a leading cause of mortality in women worldwide. The Mediterranean diet has been proposed as a healthy dietary pattern with protective effects in several chronic diseases, including breast cancer. This diet is characterized by the consumption of abundant plant foods and olive oil as the principal source of fat, which is considered one of the main components with potential antioxidant, anti-inflammatory and anticancer effects. Extra-virgin olive oil (EVOO) has several bioactive compounds, mainly including monounsaturated fatty acids, triterpenes and polyphenols, such as phenolic alcohols (e.g., hydroxytyrosol), secoiridoids (e.g., oleuropein and oleocanthal), lignans (e.g., pinoresinol) or flavonoids (e.g., luteolin). While epidemiological evidence is still limited, experimental in vivo and in vitro data have shown a protective effect of this oil and its compounds on mammary carcinogenesis. Such effects account through complex and multiple mechanisms, including changes in epigenetics, transcriptome and protein expression that modulate several signaling pathways. Molecular targets of EVOO compounds have a role in the acquisition of cancer hallmarks. Although further research is needed to elucidate their beneficial effects on human prevention and progression of the disease, evidence points to EVOO in the context of the Mediterranean diet as a heathy choice, while EVOO components may be promising adjuvants in anticancer strategies.

Embelin: A novel XIAP inhibitor for the prevention and treatment of chronic diseases

Chronic diseases are a serious health concern worldwide, especially in the elderly population. Most chronic diseases like cancer, cardiovascular ailments, neurodegenerative disorders, and autoimmune diseases are caused due to the abnormal functioning of multiple signaling pathways that give rise to critical anomalies in the body. Although a lot of advanced therapies are available, these have failed to entirely cure the disease due to their less efficacy. Apart from this, they have been shown to manifest disturbing side effects which hamper the patient's quality of life to the extreme. Since the last few decades, extensive studies have been done on natural herbs due to their excellent medicinal benefits. Components present in natural herbs target multiple signaling pathways involved in diseases and therefore hold high potential in the prevention and treatment of various chronic diseases. Embelin, a benzoquinone, is one such agent isolated from Embelia ribes, which has shown excellent biological activities toward several chronic ailments by upregulating a number of antioxidant enzymes (e.g., SOD, CAT, GSH, etc.), inhibiting anti-apoptotic genes (e.g., TRAIL, XIAP, survivin, etc.), modulating transcription factors (e.g., NF-κB, STAT3, etc.) blocking inflammatory biomarkers (e.g., NO, IL-1β, IL-6, TNF-α, etc.), monitoring cell cycle synchronizing genes (e.g., p53, cyclins, CDKs, etc.), and so forth. Several preclinical studies have confirmed its excellent therapeutic activities against malicious diseases like cancer, obesity, heart diseases, Alzheimer's, and so forth. This review presents an overview of embelin, its therapeutic prospective, and the molecular targets in different chronic diseases.

An updated review on the potential antineoplastic actions of oleuropein

Oleuropein is an ester of elenolic acid and hydroxytyrosol (3, 4-dihydroxyphenylethanol). It is a phenolic compound and the most luxuriant in olives. The detailed information related to the anticancer effects of oleuropein was collected from the internet database PubMed/Medline, ResearchGate, Web of Science, Wiley Online Library, and Cnki using appropriate keywords until the end of October 2021. Oleuropein has been shown to have antioxidant, anticancer, antiinflammatory, cardioprotective, neuroprotective, and hepatoprotective effects. Previous studies also revealed that oleuropein could effectively inhibit the malignant progression of esophageal cancer, gastric cancer, breast cancer, lung cancer, liver cancer, pancreatic cancer, ovarian cancer, prostate cancer, and cervical cancer. Recently, the role of oleuropein in inhibiting tumor cell proliferation, invasion, and migration and inducing tumor cell apoptosis has gained extensive attention. In this review, we have summarized the latest research progress related to the antioncogenic mechanisms and the potential role of oleuropein in targeting different human malignancies. Based on these findings, it can be concluded that oleuropein can function as a promising chemopreventive and chemotherapeutic agent against cancer, but its more detailed anticancer effects and underlying mechanisms need to be further validated in future preclinical as well as clinical studies.

Characterization and phytochemical constituents of Periploca hydaspidis Falc crude extract and its anticancer activities

The current study aims to investigate the anticancer potential of Periploca hydaspidis extracts against HCCLM3 and MDA-MB 231 cell lines with invasive properties and to identify molecular targets underlying its action mechanism. Cytotoxic screening of plant extracts was done via MTT assay against liver and breast cancer cell lines and GC/MS of the best cytotoxic fraction was performed to identify its chemical composition. Flow cytometry detected apoptosis and cell-cycle changes after drug treatment. The specified cells were studied for migration and invasion potential along with performing western blot analysis of proteins involved in apoptosis, cell-cycle, metastasis, and MAPK (Mitogen-activated protein kinase) cell-signaling pathway. The results revealed the crude methanol (PHM) fraction of P. hydaspidis shown dose and time dependent cell-proliferative inhibition response. GC/MS analysis detected 54 compounds of which fatty acids (29.8%), benzenoids (15.7%), and esters (14.3%) constituted the bulk. The inhibitory effect against cancer cells was linked with cell-cycle arrest at G0/G1 phase, induction of apoptosis, reduced migration and invasion capabilities post treatment. PHM induced apoptosis via downregulation of anti-apoptotic (survivin, B-cell lymphoma Extra-large; BCL-XL, X-linked inhibitor of apoptosis protein; XIAP, Myelocytomatosis; C-myc), metastatic (Matrix metallopeptidases 9/2; MMP9/2), and cell-cycle regulatory (cyclin D1 and E) proteins, whereas upregulation of pro-apoptotic proteins (Bcl-2 homologous antagonist/killer; BAK, Bcl-2-Associate X protein; BAX, cleaved caspases; 3,7,8,9, and PARP) and activation of MAPK (Jun amino-terminal kinase; JNK and P38) pathway. P38 was needed for PHM-induced apoptosis, where the inhibition of P38 by pharmacological inhibitor (SB239063) diminished the apoptotic effects. Overall, our results conclude that PHM can inhibit cell-proliferation and induce apoptotic effects by activation of P38 MAPK cell-signaling pathway. This suggests the methanol fraction of P. hydaspidis (PHM) to have anticancer compounds, potentially useful for treating liver and breast cancer. In future, one-step advance studies of PHM regarding its role in metastatic inhibition, immune response modulation for reducing tumor, and inducing apoptosis in suitable animal models would be an interesting and promising research area.

The multidimensional role of the Wnt/β-catenin signaling pathway in human malignancies

Several signaling pathways have been identified as important for developmental processes. One of such important cascades is the Wnt/β-catenin signaling pathway, which can regulate various physiological processes such as embryonic development, tissue homeostasis, and tissue regeneration; while its dysregulation is implicated in several pathological conditions especially cancers. Interestingly, deregulation of the Wnt/β-catenin pathway has been reported to be closely associated with initiation, progression, metastasis, maintenance of cancer stem cells, and drug resistance in human malignancies. Moreover, several genetic and experimental models support the inhibition of the Wnt/β-catenin pathway to answer the key issues related to cancer development. The present review focuses on different regulators of Wnt pathway and how distinct mutations, deletion, and amplification in these regulators could possibly play an essential role in the development of several cancers such as colorectal, melanoma, breast, lung, and leukemia. Additionally, we also provide insights on diverse classes of inhibitors of the Wnt/β-catenin pathway, which are currently in preclinical and clinical trial against different cancers.

Long noncoding RNAs in triple-negative breast cancer: A new frontier in the regulation of tumorigenesis

In recent years, triple-negative breast cancer (TNBC) has emerged as the most aggressive subtype of breast cancer and is usually associated with increased mortality worldwide. The severity of TNBC is primarily observed in younger women, with cases ranging from approximately 12%-24% of all breast cancer cases. The existing hormonal therapies offer limited clinical solutions in completely circumventing the TNBC, with chemoresistance and tumor recurrences being the common hurdles in the path of TNBC treatment. Accumulating evidence has correlated the dysregulation of long noncoding RNAs (lncRNAs) with increased cell proliferation, invasion, migration, tumor growth, chemoresistance, and decreased apoptosis in TNBC. Various clinical studies have revealed that aberrant expression of lncRNAs in TNBC tissues is associated with poor prognosis, lower overall survival, and disease-free survival. Due to these specific characteristics, lncRNAs have emerged as novel diagnostic and prognostic biomarkers for TNBC treatment. However, the underlying mechanism through which lncRNAs perform their actions remains unclear, and extensive research is being carried out to reveal it. Therefore, understanding of mechanisms regulating the modulation of lncRNAs will be a substantial breakthrough in effective treatment therapies for TNBC. This review highlights the association of several lncRNAs in TNBC progression and treatment, along with their possible functions and mechanisms.

Elucidating Role of Reactive Oxygen Species (ROS) in Cisplatin Chemotherapy: A Focus on Molecular Pathways and Possible Therapeutic Strategies

The failure of chemotherapy is a major challenge nowadays, and in order to ensure effective treatment of cancer patients, it is of great importance to reveal the molecular pathways and mechanisms involved in chemoresistance. Cisplatin (CP) is a platinum-containing drug with anti-tumor activity against different cancers in both pre-clinical and clinical studies. However, drug resistance has restricted its potential in the treatment of cancer patients. CP can promote levels of free radicals, particularly reactive oxygen species (ROS) to induce cell death. Due to the double-edged sword role of ROS in cancer as a pro-survival or pro-death mechanism, ROS can result in CP resistance. In the present review, association of ROS with CP sensitivity/resistance is discussed, and in particular, how molecular pathways, both upstream and downstream targets, can affect the response of cancer cells to CP chemotherapy. Furthermore, anti-tumor compounds, such as curcumin, emodin, chloroquine that regulate ROS and related molecular pathways in increasing CP sensitivity are described. Nanoparticles can provide co-delivery of CP with anti-tumor agents and by mediating photodynamic therapy, and induce ROS overgeneration to trigger CP sensitivity. Genetic tools, such as small interfering RNA (siRNA) can down-regulate molecular pathways such as HIF-1α and Nrf2 to promote ROS levels, leading to CP sensitivity. Considering the relationship between ROS and CP chemotherapy, and translating these findings to clinic can pave the way for effective treatment of cancer patients.

Beneficial role of oleuropein in sepsis-induced myocardial injury. Possible Involvement of GSK-3β/NF-kB pathway

Purpose

The present study explored the potential therapeutic role of oleuropein in sepsis-induced heart injury along with the role of GSK-3β/NF-kB signaling pathway.

Methods

Sepsis-induced myocardial injury was induced by cecal ligation and puncture (CLP) in rats. The cardiac injury was assessed by measuring the levels of cTnI and creatine kinase-MB (CK-MB). Sepsis-induced inflammation was assessed by measuring interleukin-6 (IL-6), IL-10 and HMGB1 levels. The different doses of oleuropein (5, 10, and 20 mg/kg) were given prior to CLP. Oleuropein (20 mg/kg) was administered after 6 hof CLP. The expressions of GSK-3β, p-GSK-3β (Ser9) and nuclear factor-κB (NF-κB) were measured in heart homogenates.

Results

Cecal ligation and puncture was associated with myocardial injury, an increase in IL-6, a decrease in IL-10 and an increase in HMGB1. Moreover, it decreased the ratio of p-GSK-3β/GSK-3β and increased the expression of p-NF-kB. Pretreatment with oleuropein attenuated CLP-induced myocardial injury and systemic inflammation in a dose-dependent manner. Administration of oleuropein after the onset of CLP also attenuated cardiac injury and inflammation. It also restored CLP-induced changes in the HMGB1 levels, the ratio of p-GSK-3β/GSK-3β and expression of p- NF-kB.

Conclusions

Oleuropein attenuates sepsis-induced systemic inflammation and myocardial injury by inhibiting NF-kB and GSK-3β signaling.

Potential Uses of Olive Oil Secoiridoids for the Prevention and Treatment of Cancer: A Narrative Review of Preclinical Studies

The Mediterranean diet (MD) is a combination of foods mainly rich in antioxidants and anti-inflammatory nutrients that have been shown to have many health-enhancing effects. Extra-virgin olive oil (EVOO) is an important component of the MD. The importance of EVOO can be attributed to phenolic compounds, represented by phenolic alcohols, hydroxytyrosol, and tyrosol, and to secoiridoids, which include oleocanthal, oleacein, oleuropein, and ligstroside (along with the aglycone and glycosidic derivatives of the latter two). Each secoiridoid has been studied and characterized, and their effects on human health have been documented by several studies. Secoiridoids have antioxidant, anti-inflammatory, and anti-proliferative properties and, therefore, exhibit anti-cancer activity. This review summarizes the most recent findings regarding the pharmacological properties, molecular targets, and action mechanisms of secoiridoids, focusing attention on their preventive and anti-cancer activities. It provides a critical analysis of preclinical, in vitro and in vivo, studies of these natural bioactive compounds used as agents against various human cancers. The prospects for their possible use in human cancer prevention and treatment is also discussed.

Brucein D modulates MAPK signaling cascade to exert multi-faceted anti-neoplastic actions against breast cancer cells

Breast cancer is a prominent type of malignancy among women with a high rate of mortality. A number of previous studies have demonstrated the anticancer potential of brucein D (BD), a quassinoid extracted from Brucea javanica, against the cancers of the pancreas, bone, and liver. We investigated the impact of BD on apoptotic as well on mitogen-activated protein kinase (MAPK) signaling cascades in breast cancer cells. The effect of BD on p38 MAPK and JNK signaling pathways and its downstream functions was deciphered in both MDA-MB-231 and MCF-7 cell lines. We noted that BD decreased the viability of breast cancer cells without affecting the growth of healthy mammary epithelial cells (MCF-10A). Flow cytometric analysis revealed that BD can increase sub-G1 cells and enhanced annexin-V-PI stained cells. The apoptogenic impact of BD was further substantiated by cleavage of procaspase-3/8 and downregulation of antiapoptotic proteins (Bcl-xL, XIAP, and survivin). Furthermore, BD also downmodulated the migratory ability, and chemokine triggered invasion of breast cancer cells. Interestingly, the pharmacological inhibition of p38 MAPK and JNK kinases abrogated the observed anticancer actions of BD. Overall, the data indicated that BD can induce substantial apoptosis and interfere with cellular invasion by modulating MAPK signaling pathway in breast cancer cells.

The Anti-cancer Effect of Olea europaea L. Products: a Review

PURPOSE OF REVIEW

The olive tree (Olea europaea L.) has featured as a significant part of medicinal history, used to treat a variety of ailments within folk medicine. The Mediterranean diet, which is rich in olive products, is testament to Olea europaeas positive effects on health, associated with reduced incidences of cancer and cardiovascular disease. This review aims to summarise the current literature regarding the therapeutic potential of Olea europaea products in cancer, detailing the possible compounds responsible for its chemotherapeutic effects.

RECENT FINDINGS

Much of the existing research has focused on the use of cell culture models of disease, demonstrating Olea europaea extracts, and specific compounds within these extracts, have efficacy in a range of in vitro and in vivo cancer models. The source of Olea europaeas cytotoxicity is yet to be fully defined; however, compounds such as oleuropein and verbascoside have independent cytotoxic effects on animal models of cancer. Initial results from animal models are promising but need to be translated to a clinical setting. Treatments utilising these compounds are likely to be well tolerated and represent a promising direction for future research.

Rationalizing the therapeutic potential of apigenin against cancer

BACKGROUND

Despite the remarkable advances made in the diagnosis and treatment of cancer during the past couple of decades, it remains the second largest cause of mortality in the world, killing approximately 9.6 million people annually. The major challenges in the treatment of the advanced stage of this disease are the development of chemoresistance, severe adverse effects of the drugs, and high treatment cost. Therefore, the development of drugs that are safe, efficacious, and cost-effective remains a 'Holy Grail' in cancer research. However, the research over the past four decades shed light on the cancer-preventive and therapeutic potential of natural products and their underlying mechanism of action. Apigenin is one such compound, which is known to be safe and has significant potential in the prevention and therapy of this disease.

AIM

To assess the literature available on the potential of apigenin and its analogs in modulating the key molecular targets leading to the prevention and treatment of different types of cancer.

METHOD

A comprehensive literature search has been carried out on PubMed for obtaining information related to the sources and analogs, chemistry and biosynthesis, physicochemical properties, biological activities, bioavailability and toxicity of apigenin.

KEY FINDINGS

The literature search resulted in many in vitro, in vivo and a few cohort studies that evidenced the effectiveness of apigenin and its analogs in modulating important molecular targets and signaling pathways such as PI3K/AKT/mTOR, JAK/STAT, NF-κB, MAPK/ERK, Wnt/β-catenin, etc., which play a crucial role in the development and progression of cancer. In addition, apigenin was also shown to inhibit chemoresistance and radioresistance and make cancer cells sensitive to these agents. Reports have further revealed the safety of the compound and the adaptation of nanotechnological approaches for improving its bioavailability.

SIGNIFICANCE

Hence, the present review recapitulates the properties of apigenin and its pharmacological activities against different types of cancer, which warrant further investigation in clinical settings.

Olive leaf extract impairs mitochondria by pro-oxidant activity in MDA-MB-231 and OVCAR-3 cancer cells

Breast and ovarian cancers are the leading and fifth reason for tumor death among females, respectively. Recently, many studies demonstrated antiproliferative activities of natural aliments in cancer. In this study, we investigated the antitumor potential of Olive Leaf Extract (OLE) in triple-negative breast and ovarian cancer cells. A HPLC/DAD analysis on OLE has been performed to assess the total polyphenolics and other secondary metabolites content. HCEpiC, MDA-MB-231, and OVCAR-3 cell lines were used. MTS, Cytofluorimetric, Western Blot analysis were performed to analyze cell viability, cell proliferation, apoptosis, and oxidative stress. Fluorimetric and IncuCyte® analyses were carried out to evaluate apoptosis and mitochondrial function. We confirmed that OLE, containing a quantity of oleuropein of 87 % of the total extract, shows anti-proliferative and pro-apoptotic activity on MDA-MB-231 cells. For the first time, our results indicate that OLE inhibits OVCAR-3 cell viability inducing cell cycle arrest, and it also increases apoptotic cell death up-regulating the protein level of cleaved-PARP and caspase 9. Moreover, our data show that OLE treatment causes a significant decrease in mitochondrial functionality, paralleled by a reduction of mitochondrial membrane potential. Interestingly, OLE increased the level of intracellular and mitochondrial reactive oxygen species (ROS) together with a decreased activity of ROS scavenging enzymes, confirming oxidative stress in both models. Our data demonstrate that mitochondrial ROS generation represented the primary mechanism of OLE antitumor activity, as pretreatment with antioxidant N-acetylcysteine prevented OLE-induced cell cycle arrest and apoptosis.

An overview of the potential anticancer properties of cardamonin

Cancer is one of the leading causes of mortality, contributing to 9.6 million deaths globally in 2018 alone. Although several cancer treatments exist, they are often associated with severe side effects and high toxicities, leaving room for significant advancements to be made in the field. In recent years, several phytochemicals from plants and natural bioresources have been extracted and tested against various human malignancies using both in vitro and in vivo preclinical model systems. Cardamonin, a chalcone extracted from the Alpinia species, is an example of a natural therapeutic agent that has anti-cancer and anti-inflammatory effects against human cancer cell lines, including breast, lung, colon, and gastric, in both in vitro culture systems as well as xenograft mouse models. Earlier, cardamonin was used as a natural medicine against stomach related issues, diarrhea, insulin resistance, nephroprotection against cisplatin treatment, vasorelaxant and antinociceptive. The compound is well-known to inhibit proliferation, migration, invasion, and induce apoptosis, through the involvement of Wnt/β-catenin, NF-κB, and PI3K/Akt pathways. The good biosafety and pharmacokinetic profiling of cardamonin satisfy it as an attractive molecule for the development of an anticancer agent. The present review has summarized the chemo-preventive ability of cardamonin as an anticancer agent against numerous human malignancies.

Effects of oleuropein on tumor cell growth and bone remodelling: Potential clinical implications for the prevention and treatment of malignant bone diseases

Oleuropein (Ole) is the main bioactive phenolic compound present in olive leaves, fruits and olive oil. This molecule has been shown to exert beneficial effects on several human pathological conditions. In particular, recent preclinical and observational studies have provided evidence that Ole exhibits chemo-preventive effects on different types of human tumors. Studies undertaken to elucidate the specific mechanisms underlying these effects have shown that this molecule may thwart several key steps of malignant progression, including tumor cell proliferation, survival, angiogenesis, invasion and metastasis, by modulating the expression and activity of several growth factors, cytokines, adhesion molecules and enzymes involved in these processes. Interestingly, experimental observations have highlighted the fact that most of these signalling molecules also appear to be actively involved in the homing and growth of disseminating cancer cells in bones and, ultimately, in the development of metastatic bone diseases. These findings, and the experimental and clinical data reporting the preventive activity of Ole on various pathological conditions associated with a bone loss, are indicative of a potential therapeutic role of this molecule in the prevention and treatment of cancer-related bone diseases. This paper provides a current overview regarding the molecular mechanisms and the experimental findings underpinning a possible clinical role of Ole in the prevention and development of cancer-related bone diseases.

Potential of guggulsterone, a farnesoid X receptor antagonist, in the prevention and treatment of cancer

Cancer is one of the most dreadful diseases in the world with a mortality of 9.6 million annually. Despite the advances in diagnosis and treatment during the last couple of decades, it still remains a serious concern due to the limitations associated with currently available cancer management strategies. Therefore, alternative strategies are highly required to overcome these glitches. The importance of medicinal plants as primary healthcare has been well-known from time immemorial against various human diseases, including cancer. Commiphora wightii that belongs to Burseraceae family is one such plant which has been used to cure various ailments in traditional systems of medicine. This plant has diverse pharmacological properties such as antioxidant, antibacterial, antimutagenic, and antitumor which mostly owes to the presence of its active compound guggulsterone (GS) that exists in the form of Z- and E-isomers. Mounting evidence suggests that this compound has promising anticancer activities and was shown to suppress several cancer signaling pathways such as NF-κB/ERK/MAPK/AKT/STAT and modulate the expression of numerous signaling molecules such as the farnesoid X receptor, cyclin D1, survivin, caspases, HIF-1α, MMP-9, EMT proteins, tumor suppressor proteins, angiogenic proteins, and apoptotic proteins. The current review is an attempt to summarize the biological activities and diverse anticancer activities (both in vitro and in vivo) of the compound GS and its derivatives, along with its associated mechanism against various cancers.

Genistin attenuates cellular growth and promotes apoptotic cell death breast cancer cells through modulation of ERalpha signaling pathway

Estrogen receptor alpha (ERα) is a vital molecular target in ER-positive breast cancer. Genistin (GS) is one of isoflavones that can exert diverse pharmacological effects including that of anti-proliferation, anti-tumor angiogenesis, induce cell cycle arrest and apoptosis. Here, we examined the efficacy of GS as an anti-cancer agent against breast cancer cells. We observed that GS exhibited more cytotoxic activity against MCF-7 cells than MDA-MB-231cells. We found that GS caused negative regulation of ERα. It also effectively down-modulated ER nuclear translocation as well DNA binding activity in breast cancer cells. Moreover, GS effectively induced apoptosis and suppressed levels of oncogenic markers in MCF-7 cells. Interestingly, in ERα knocked-down MCF-7 cells, cell viability was found to be increased and the levels of cleaved PARP was abolished. We found completely contrasting results in ERα overexpressed MDA-MB-231 cells, where cell viability was decreased and expression level of apoptotic markers was enhanced. Our results demonstrate that GS can suppress ERα signaling and can be useful for prevention and therapy of ER-positive breast cancer.

Circular RNA circABCC4 acts as a ceRNA of miR-154-5p to improve cell viability, migration and invasion of breast cancer cells in vitro

Breast cancer is one of the dominant cancers of women-related death universal. This inquiry aims to disclose the probable role of circABCC4 in breast cancer. The level of circABCC4 was discovered through qRT-PCR. The reactions of circABCC4 and miR-154-5p on the cell viability, apoptosis, migration as well as invasion were, respectively, inspected by CCK-8, flow cytometry, and transwell assays. The association betwixt circABCC4 and miR-154-5p was investigated. The accumulation of NF-κB and Wnt/β-catenin pathway proteins was discovered through Western blot. The expression of circABCC4 was far great in tumor tissues than in normal tissues. Knockdown of circABCC4 could subdue cell viability, migration, invasion, and enhance apoptosis in breast cancer cell lines. CircABCC4 negatively regulated the manifestation of miR-154-5p and shared binding sites with the latter. Suppression of miR-154-5p expression partially conversed the repressive effect of circABCC4 knockdown on breast cancer cell viability, migration, invasion, and NF-κB and Wnt/β-catenin pathways. CircABCC4 knockdown repressed breast cancer cells viability, migration, and invasion by up-regulating miR-154-5p via inhibiting NF-κB and Wnt/β-catenin signal pathways.

Production of Plant-Derived Oleuropein Aglycone by a Combined Membrane Process and Evaluation of Its Breast Anticancer Properties

Natural products and herbal therapies represent a thriving field of research, but methods for the production of plant-derived compounds with a significative biological activity by synthetic methods are required. Conventional commercial production by chemical synthesis or solvent extraction is not yet sustainable and economical because toxic solvents are used, the process involves many steps, and there is generally a low amount of the product produced, which is often mixed with other or similar by-products. For this reason, alternative, sustainable, greener, and more efficient processes are required. Membrane processes are recognized worldwide as green technologies since they promote waste minimization, material diversity, efficient separation, energy saving, process intensification, and integration. This article describes the production, characterization, and utilization of bioactive compounds derived from renewable waste material (olive leaves) as drug candidates in breast cancer (BC) treatment. In particular, an integrated membrane process [composed by a membrane bioreactor (MBR) and a membrane emulsification (ME) system] was developed to produce a purified non-commercially available phytotherapic compound: the oleuropein aglycone (OLA). This method achieves a 93% conversion of the substrate (oleuropein) and enables the extraction of the compound of interest with 90% efficiency in sustainable conditions. The bioderived compound exercised pro-apoptotic and antiproliferative activities against MDA-MB-231 and Tamoxifen-resistant MCF-7 (MCF-7/TR) cells, suggesting it as a potential agent for the treatment of breast cancer including hormonal resistance therapies.